Variable power control electronic cigarette

ABSTRACT

Disclosed are an electronic cigarette and methods for controlling the power to the electronic cigarette which provides various modes of operation, including both regulated and no-regulated mode. The method is implemented m the form of an electronic power control program that controls the constituent parts of the electronic cigarette, including the battery, atomizer, heating element, smoke liquid or juice, and related circuitry.

PRIORITY CLAIM

This application claims priority as a Continuation to PCT ApplicationNumber PCT/US2012/024353, filed on Feb. 8, 2012, which claims priorityto U.S. Provisional patent application No. 61/441,133, filed on Feb. 9,2011, each of which are incorporated by reference.

TECHNICAL FIELD

This invention relates generally to electronic cigarettes and morespecifically to a variable power control program for electroniccigarette systems.

BACKGROUND ART

Electronic cigarettes are becoming a popular alternative to tobaccosmoking because of the many advantages that they offer. The advantagesof electronic cigarettes may include the absence of tar, odor, ash,pollution, and combustion by-products as compared, to traditionaltobacco smoking,

However, there are still several factors holding users back from fullyembracing this promising device. The addiction to smoking is not simplyan addiction to nicotine; it is a habit that has many facets, includingphysiological, psychological, social, tactile, etc. Therefore, a largepart of creating an ideal electronic cigarette is to provide a positiveuser experience which is increasingly similar to tobacco smoking. Thismeans that the electronic cigarette has to require minimal priming,produce consistent “smoke” volume, and always be available with reliableand extended battery life.

An electronic cigarette typically comprises a battery, an atomizer, acontainer having smoke juice, and a power control circuit. The batteryis used to power the circuit and the atomizer, where the atomizer heatsthe smoke juice to create smoke to vapor, which is inhaled by a user.“Smoke” volume is dependent on the power output of the device, which isa function of voltage squared, divided by the resistance. Accordingly,in the usual arrangement, battery output voltage is directlyproportional to “smoke” volume.

Earlier versions of electronic cigarettes often failed to providepositive user experience. Most electronic cigarettes have unregulatedlithium-polymer battery cells that start off with a high voltage ofabout 4.2 volts, and drops gradually to about 3.0 volts as the cell'scharge is depleted. This arrangement relies on the battery's naturalpower degradation to regulate the production of smoke. Thus, as thebattery cell is depleted, voltage in the battery naturally decreases andthe “smoke” volume noticeably drops, making for an inconsistent smokingexperience.

Another disadvantage with these unregulated electronic cigarettes isthat the power supplied during power-up or priming” are very high,tending to produce excessive heat. After priming, the battery continuesoperating at its maximum output (minus any power loss due to the primingstage) and the excessive heat produced does not have enough time todissipate, resulting in high internal and external temperatures on thehousing of the cartridge. It often happens that after a dozen or sopuffs, the smoke juice and materials surrounding the heating elementstart to overheat and acquire an unpleasant burning smell. Moreconcerning, the atomizer housing becomes so hot that it can burn thefingers and/or lips of the user.

Newer versions of electronic cigarettes often incorporate a circuit toreduce output power at specific points during operation by regulatingthe output voltage of the battery at all times during operation. Thepurpose of regulation is to limit the output voltage of the batterythroughout the smoking cycle to the same voltage level that the batterywill have at its depleted state (i.e., at approximately 3 volts),thereby maintaining a uniform lower output voltage. This is supposed toensure that the user has a uniform experience from the first puff to thelast, with no degradation in “smoke” volume as the battery discharges,while conserving energy and extending battery life.

Unfortunately, there is a downside to this approach. In order for anatomizer to produce enough “smoke” volume, it needs to be sufficientlywarmed up, which is hard to achieve in a short period of time when thebattery output voltage is initially limited by the regulating circuit. Aregulated voltage arrangement therefore requires more time during thepriming stage in order to warm up the atomizer, and, if the user takes apuff before the atomizer is completely primed, it leads to lesssmoke/vapor production at the beginning, thereby impairing userexperience because the initial puffs are not satisfying. Moreover, theseinitial user puffs essentially act as the “priming” for the device. Fora first-time user of the electronic cigarette, the first few weakpuffs—with little “smoke” volume—could be a disappointing experience,causing him to reject the product. It simply is not desirable for theuser to be responsible for priming the device, as it can be a nuisance.Therefore, neither the unregulated system, nor the fully regulatedsystem is a sufficient solution to ensure an optimal smoking experienceand long battery life. Accordingly, there is a need in the art for amore dynamic or variable power control program that can provide a bettersmoking experience for the user.

SUMMARY OF THE INVENTION

The invention comprises an electronic cigarette and methods forcontrolling the power to the electronic cigarette which provides variousmodes of operation, including both regulated and un-regulated mode. Themethod is implemented in the form of an electronic power control programthat controls the constituent parts of the electronic cigarette,including the battery, atomizer, heating element, smoke liquid or juice,and related circuitry.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exemplary voltage versus time plot, depicting the responseof one embodiment of the present invention.

FIG. 2 is a table depicting the characteristics of the various modes ofoperation for one embodiment of the present invention.

FIG. 3 is a table depicting the characteristics of the various modes ofoperation for another embodiment of the present invention.

FIG. 4 is a table depicting the characteristics of the various modes ofoperation for another embodiment of the present invention, based ontemperature feedback.

FIG. 5 is an exemplary voltage versus temperature plot, depicting theresponse of another embodiment of the present invention.

FIG. 6 is a schematic of the circuitry inside an electronic cigarettewhich contains an embodiment of Power Control Program in which the powermode are preset and determined by “Pause” duration.

FIG. 7 is a schematic of the circuitry inside an electronic cigarettewhich contains an embodiment of Power Control Program, in which thepower modes are preset and determined by a temperature feedback loop.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The invention in embodiments thereof discloses an electronic cigaretteand methods for controlling the power to an electronic cigarette whichprovides various modes of operation, including both regulated andunregulated mode. The method is implemented in the form of an electronicpower control program that controls the constituent parts of theelectronic cigarette, including the battery, atomizer, heating elementsmoke liquid or juice, and related circuitry.

When an electronic cigarette is first called into operation, it needs tobe warmed up before the atomizer can produce smoke or vapor. Therefore,some embodiments of the power control program of the present inventionhave a first mode of operation, known as the “self-priming mode,” whichpermits the heating element to be initially warmed up to the battery'smaximum output voltage. This automatic “priming” mode reduces orcompletely eliminates the need for a user to manually prime the device.The “self-priming mode” is configured such that the heating elementremains active for a pre-determined amount of time in order to assureproper priming. For example, as shown in FIG. 1, when the smokerinitiates the first puff, the “self-priming mode” is initiated and thebattery produces up to its maximum voltage (in this case, 4.2 V) for apredetermined amount of time (in this case, 5 seconds), even if the useractivates the sensor for less than the predetermined amount of time.

If a consecutive puff follows within a short time after the one beforeit, then there is no need to “prime” the heating element again, and thepower control program can switch to the “regulated mode.” By example,FIG. 1 depicts activation of “regulated mode” after 5 seconds, at 3 V.This “regulated mode” conserves battery power while normalizing “smoke”volume to a constant level, providing a uniform smoking experience.However, it is understood that, in some embodiments, it is onlydesirable to stay in “regulated” mode if one is smoking at normalintervals. Thus, if a user takes a long pause between puffs, then it ispreferable to switch back to “self-priming mode” because the heatingelement has cooled off to the point where the voltage supplied in the“regulated mode” is insufficient to produce the proper amount of smokeand/or vapor. Accordingly, in some embodiments, mode selection may bedictated by the length of time between puffs.

In some embodiments, a third mode, called “safety mode” may be activatedin certain, circumstances. For example, if consecutive puffs are tooclose together in time, the atomizer might accumulate too much heat,causing it to overheat. Therefore, the power control program is adaptedto trigger a “safety mode,” where the voltage is dropped below thenominal voltage during “regulated mode.” “Safety mode,” therefore, willprovide just enough power to evaporate additional smoke juice, but notenough power to cause excessive heat accumulation and/or an increase intemperature of the component parts of the electronic cigarette.

In accordance with the embodiments of the present invention that aretime-based, the lapse between puffs or the “pause” determines which modeshould be used to power the current puff. Each mode has “pause” value ora range of pause values associated with it, so that for each pausebetween puffs, the control program can identify which power mode shouldbe triggered for that specific puff(s). FIG. 2 presents data from onesuch embodiment of the present invention, utilizing three modes ofoperation, “self-priming mode” “regulated mode,” and “safety mode.”

Another aspect of the present invention provides that the power controlprogram receives feedback as to when a puff is initiated and when itends. In some embodiments, this information is fed back to the controlprogram from an air-flow sensor in the electronic circuit, which isactivated based on user inhalation. Accordingly, a timing mechanism maybe in communication with the air-flow sensor such that the timingmechanism is activated after the completion of every puff, and measuresthe time between puffs, i.e. “pause” (the timing mechanism is restartedafter every puff). Accordingly, the power control program includes theability to compare the measured pause against the pre-set pause range ofeach mode, to determine which mode should be triggered for the currentpuff Also contemplated is a mechanism that can instantaneously adjustthe output voltage according to the pre-assigned settings for a specificmode.

There are many common factors that determine the pause values of themodes and the output voltage level during each mode. Both the pausevalues and output voltage depend on thermal characteristics of theelectronic cigarette including its construction, the configuration ofits elements, material makeup of its components, its heat losscoefficient, as well as ambient temperature, pressure and other suchfactors. For example, frequent puffing does not allow enough time forthe electronic cigarette to cool down, which affects the cumulativetemperature of the unit. Electrical resistance of the heating elementalso greatly affects output voltage, because output voltage is inverselyproportional to the electrical resistance. The construction of theelectronic cigarette also affects how the passing air cools the heatingelement within the body of the cigarette. Further, the material makeupof the components affects the heat dissipation characteristics. All ofthese factors must he considered with determining the pause values ofthe particular modes for a given electronic cigarette configuration.

In one example, the pause value ranges and output voltage of theoperation modes are pre-programmed into the microprocessor or microchipthat comprise the power control program in the electronic cigarette. Todetermine those settings, actual tests are performed on the specificelectronic cigarette by varying the pause between puffs and outputvoltage. Empirical data is gathered and optimal settings are selectedbased on the data. Presently available data shows that for mostatomizers known in the art, where the internal resistance ranges from2.2 ohms to 3.6 ohms, the “self-priming mode” is best set to run for 5seconds (even if the user puffs less than that), and the output voltageshould be non-regulated, i.e. the maximum output voltage of the battery.In some embodiments, the pause range for the “self-priming mode” shouldideally be 30 seconds to infinity, meaning that the device remains in“self-priming mode” unless the next puff occurs within 30 seconds of theinitial puff Thus, it is not necessary to keep the timing mechanismmeasuring time beyond 30 seconds, because the pause value of 30 secondsalready means that the atomizer is cooled off, and there is no need towaste battery power to run the timer. Instead, the power control programis adapted to stop the clock at 30 seconds. When a new puff is detected,the program checks either if the timer has stopped counting or if it isat 30 seconds, and if yes, it re-triggers the “self-priming mode.”

If the new puff occurs less than 30 seconds from the initial puff, adifferent mode, i.e. “regulated mode” or “safety mode” of operationshould be initiated. Accordingly, in some embodiments and for exemplarypurposes, the ideal pause value range for “regulated mode” is 4 to 29seconds, and the voltage should be regulated at 3.0 volts. In someembodiments, the ideal pause range value for “safety mode” is 0 to 3seconds, and the voltage should be regulated at 2.8 volts. FIGS. 2 and 6depict this configuration.

In further embodiments of the present invention, there are additionalmodes pre-programmed into the power control program. For example, the“safety” mode can be broken down further into several modes, each onehaving its own pause range and power output. Also, there could beseveral “self-priming” modes, depending on the pause duration and thecooling of the atomizer. FIGS. 3 and 6 depict this configuration.Accordingly, it is understood that the power control program of thepresent invention need not be limited to a certain number of powermodes, rather any number of modes may be implemented as desired.

In further embodiments of the present invention, the modes of operationof the power control circuit are dynamic and/or reactive rather thanpre-programmed. In these embodiments, the power output of the mode ispre-programmed, but the pause range values are replaced by a temperaturefeedback system. Instead of measuring time between puffs, the powercontrol program receives temperature reading from temperaturesensor/sensors inside the electronic cigarette, and it calculates whichmode the current puff should trigger. In such an embodiment, the powercontrol program has each temperature range assigned to a specific modeof operation. In some embodiments, the output voltage is adjusted atevery puff, depending on the real-time temperature of the atomizer.FIGS. 4, 5, and 7 depict an example of this configuration.

It will be understood that the preferred embodiments of the presentinvention have been disclosed by way of example and that othermodifications and alterations may occur to those skilled in the artwithout departing for the scope of the disclosure herein.

1. An electronic cigarette comprising: a power source; a sensor forsensing airflow of a puff; a power control program configured to monitoror control the power source and the sensor, wherein the power controlprogram includes a plurality of operating modes.
 2. The electroniccigarette of claim 1 wherein each of the plurality of operating modescomprises a change from the power source.
 3. The electronic cigarette ofclaim 2 wherein the change from the power source comprises a voltagelevel, further wherein each of the plurality of operating modescomprises a voltage level.
 4. The electronic cigarette of claim 1wherein the operating modes comprise a self-priming mode, a regulatedmode, and a safety mode.
 5. The electronic cigarette of claim 4 whereinthe self-priming mode comprises an increase in power from the powersource at start up, the regulated mode comprises a decrease in powerfrom the self-priming mode, and the safety mode comprises a decrease inpower from the regulated mode.
 6. The electronic cigarette of claim 5wherein the self-priming mode is activated upon initializing of theelectronic cigarette and directs the power source to provide a maximumvoltage.
 7. The electronic cigarette of claim 5 wherein the regulatedmode is activated when the sensor is activated twice within apredetermined time interval and directs the power source to provide apredetermined nominal voltage.
 8. The electronic cigarette of claim 5wherein the safety mode is activated when the sensor is activated twicein less than a minimum predetermined amount of time and directs thepower source to provide a lower than nominal voltage to decreaseaccumulation of heat within the electronic cigarette.
 9. The electroniccigarette of claim 1 wherein a number of the plurality of modes isincreased to approximate a continuous function.
 10. The electroniccigarette of claim 1 wherein a mode from the operating modes is selectedbased on feedback to the power control program including at least one ofa length of the puff, a time between puffs, or a temperature of theelectronic cigarette.
 11. The electronic cigarette of claim 1 whereinthe power source comprises a battery.
 12. An electronic cigarettecomprising: an electric power source; a sensor for sensing airflow of apuff; a processor configured to control the electric power source basedon feedback from at least one of a length of the puff or a time betweenpuffs.
 13. The electronic cigarette of claim 12 wherein power providedby the electric power source varies based on the feedback.
 14. Theelectronic cigarette of claim 13 wherein a voltage level from theelectric power source is set based on at least one of the length of thepuff or the time between the puffs.
 15. The electronic cigarette ofclaim 14 wherein the voltage levels correspond to operating modes, suchthat the operating modes are selected based on at least one of thelength of the puff or the time between the puffs.
 16. The electroniccigarette of claim 12 further comprising: an atomizer; a heatingelement; and a container for a liquid that is atomized through heat fromthe heating element.
 17. An electronic cigarette comprising: an electricpower source; a temperature sensor measuring a temperature of theelectronic cigarette; and a power control program configured to controlthe electric power source based on the temperature.
 18. The electroniccigarette of claim 17 wherein power provided by the electric powersource corresponds to a voltage level from the electric power source.19. The electronic cigarette of claim 18 wherein each of the voltagelevels corresponds to a particular temperature range.
 20. The electroniccigarette of claim 17 wherein the power control program is furtherconfigured to control the electric power source based on feedback fromat least one of a length of a puff or a time between puffs.